class Solution:
    def reverseString(self, s) -> None:
        """
        Do not return anything, modify s in-place instead.
        """
        start = 0
        end = len(s)-1
        while start<end:
            s[start],s[end] = s[end],s[start]
            start += 1
            end -= 1

if __name__ == '__main__':
    so = Solution()
    nums1 = ["h","e","l","l","o"]
    r = so.reverseString(nums1)
    print(nums1)
